One of the special features of this program is that the four individual projects are absolutely dependent upon patient material, since the questions to be addressed arise from the variability of individual patient response (i.e., Why do some patients develop secondary cancers and others not?). In addition to patient enrollment, chart review, and data collection, we propose again to incorporate within the original Core A formal support for database coordination, statistical analyses, and computation. The entire program project and the individual projects require close and continuing statistical collaboration to insure appropriate study design, data management and retrieval, and subsequent analyses of results. In this way, any problems with the study design that may arise may be corrected, and interim analyses of data may be disseminated promptly among the project investigators. The Patient Access Core have the dual missions of data management and statistical analysis which are critical to the successful completion of the proposed investigations and necessary to support and link together the results that will come from the various laboratories. In order to provide an orderly access to patient material and to maintain records, we propose to continue our Core A component to manage these functions. Requests for specific clinical materials (blood or marrow cells, tumor tissues, or cell lines from specific patients) will be directed by each project P.I. to Core A of the Program. After collection, the clinical specimens will be logged in and transmitted to Core B for processing and delivery to the individual projects.